•
•
133Xe Muscle Clearance: A Screening Test for Arterial Occlusive Disease 1
Nuclear Medicine
Rodney V. Pozderac, M.D., Thomas A. Miller, M.D., and S. Martin Lindenauer, M.D. 133Xe muscle clearance following ischemic exercise provides a simple, well-tolerated screening procedure for evaluating patients suspected of having arterial occlusive disease in the lower extremeties and may be useful in the follow-up of patients who have undergone corrective arterial surgery. It can be performed in nuclear medicine units capable of doing renography, and the authors feel it should be used prior to undertaking more invasive procedures such as arteriography. Methods and results of tests involving 92 legs in men are described. INDEX TERMS: Arteriosclerosis. Extremeties, blood supply. Muscles, blood supply. Xenon, radioactive
Radiology 117:633-635, December 1975
I,
•
•
the anterior tibialis muscle 10-12 cm distal to the inferior margin of the patella and 2-4 cm lateral to the tibial crest at an angle of 45° and a depth of 2 cm, using a 26 gauge needle. Initial counting rates were in the range of 25,000-60,000 cpm. Care was taken not to inject any air bubbles, and the needle was removed from the muscle approximately 10 sec. after the injection. The subject's feet were positioned slightly beyond the edge of the stretcher to allow for unimpeded dorsiflexion of the foot. A Velcro-lined sphygmomanometer thigh cuff was placed proximal to the knee and the injection site was positioned 15-18 cm beneath the center of a low-energy (250-keV) parallel-hole collimator of a Nuclear Chicago Pho/Gamma 11/ camera. A ratemeter with a linear scale, a strip-chart recorder, and a 30% spectrometer window were used. Following the injection of 133Xe, the thigh cuff was inflated and maintained at 200-230 mm Hg. The subject then rhythmically dorsiflexed and extended his foot at a rate of 30 times/min. for 4 Y2 min. All subjects were told to exercise as fast and as long as possible at the end of the 4 Y2-min. period. At no time was the duration of ischemia shortened to less than 5 min., and most individuals finished exercising within 5% min. At the end of the ischemic exercise phase, the thigh cuff was rapidly deflated and the rate of disappearance of the radionuclide from the injection site was recorded on a strip chart starting with the initiation of the ischemic exercise phase (in order to confirm the adequacy of the ischemia) and for 5 min. during the ensuing hyperemia. This process was followed for both legs. Maximum blood flow during hyperemia was calculated by plotting the counting rate on semilog paper against time in minutes on the linear scale and using the formula (2)
1964 Lassen et el: (1) first described the use of 133Xe to measure blood flow in the muscles of the lower extremity. Since then the measurement of muscle blood flow (MBF) has not been widely utilized as a routine procedure in many nuclear medicine units, due to the need for elaborate exercise equipment, specially constructed detectors, and maneuvers requiring lengthy intervals to provide meaningful data. Our method for evaluating arterial occlusive disease in the lower extremities avoids these objections and is simple, rapid, and clinically useful. N
METHODS AND MATERIALS
Patients seen in the General Surgery Clinic at the Ann Arbor V. A. Hospital between November 1972 and May 1973 who were suspected of having arterial occlusive disease involving the legs on the basis of the history or physical examination were studied by arteriography. Based on these findings, the legs were assigned to one of three groups. Group I included those limbs demonstrating arterial occlusive disease with poor collateral formation about the aortoiliac, iliofemoral, or femoropopliteal segments. Group" included those having arterial occlusive disease with good collateral formation about the aforementioned segments. Group III included those limbs considered normal on arteriographic examination. Within one week of arteriography, maximum MBF was determined by 133Xe muscle clearance in 62 limbs of 31 men. 133:)(e muscle clearance was also determined in 30 timbs of 15 men who displayed no evidence of arterial occlusive disease by history or physical examination. Informed consent was obtained from all participants. Maximum MBF was determined for each limb as follows. With the subject supine on a stretcher 0.25 ml of 133Xe (200-500 1L Ci) in saline solution was injected into
MBF
=
100 x A x K
1 From the Nuclear Medicine Service and Surgery Service, VA Hospital, and Department of Surgery, University of Michigan, Ann Arbor, Mich. Accepted for publication in May 1975. elk
633
634
V.
RODNEY
,
100
\
\
70
,
" ,,
Subject R.J, MBF = 100 x )" x Ln 2
TY2
w
~
ou
= 38,8 cc /IOOgm/min
7 CUFF RELEASE
5
l,.
ISCHEMIC EXERCISE
3
.,
HYPEREMIA
456
7
8
10
9
TIME (min)
Fig. 1. Calculation of maximum MBF in the anterior tibialis muscle in a normal subject using the 13 3 Xe clearance curve.
80 70
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~~ 50
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~
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,
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cers, gangrenous or pregangrenous skin changes, or pain at rest. The MBF was 14.8 ± 6.0 ml/100 g muscle/ min. (mean ± 1 s.d.; p 0.001 compared to normal limbs) with a range of 4.1-25.7 ml/100 g muscle/min. Nine limbs (mean patient age 54.8 yr, range 46-63 yr.) were shown by arteriography to have arterial occlusive disease with good collateral flow (Group II). This group consisted of 5 patients whose other limb was assigned to Group I (arterial occlusive disease with poor collateral formation) and 2 patients in whom both limbs showed arterial occlusive disease with good collateral formation. These last 2 were thought clinically to have mild intermittent claudication. The maximum MBF for their limbs was 30.1 ± 1.8 mil 100 g muscle/min. (mean ± 1 s.d.: p 0.001 compared to normal limbs) with a range of 28.1-32.6 ml/100 g muscle/min. Maximum MBF for the 9 limbs comprising Group III (patient mean age 47 yr., range 45-50 yr.) was 43.7 ± 4.0 mil 100 g muscle/min. (mean ± 1 s.d.) with a range of 38.8-49.0 ml/ 100 g muscle/min. This group included 3 patients whose opposite limb was assigned to Group I; maximum MBF determinations correctly identified unilateral involvement with arterial occlusive disease. Three additional patients who had symptoms suggestive of atypical claudication were found to have normal arteriograms and MBF studies. All limbs in Group III had maximum MBF determinations within the range of normal.
•
133Xe Muscle Clearance: A Screening Test for Arterial Occlusive Disease 1
Nuclear Medicine
Rodney V. Pozderac, M.D., Thomas A. Miller, M.D., and S. Martin Lindenauer, M.D. 133Xe muscle clearance following ischemic exercise provides a simple, well-tolerated screening procedure for evaluating patients suspected of having arterial occlusive disease in the lower extremeties and may be useful in the follow-up of patients who have undergone corrective arterial surgery. It can be performed in nuclear medicine units capable of doing renography, and the authors feel it should be used prior to undertaking more invasive procedures such as arteriography. Methods and results of tests involving 92 legs in men are described. INDEX TERMS: Arteriosclerosis. Extremeties, blood supply. Muscles, blood supply. Xenon, radioactive
Radiology 117:633-635, December 1975
I,
•
•
the anterior tibialis muscle 10-12 cm distal to the inferior margin of the patella and 2-4 cm lateral to the tibial crest at an angle of 45° and a depth of 2 cm, using a 26 gauge needle. Initial counting rates were in the range of 25,000-60,000 cpm. Care was taken not to inject any air bubbles, and the needle was removed from the muscle approximately 10 sec. after the injection. The subject's feet were positioned slightly beyond the edge of the stretcher to allow for unimpeded dorsiflexion of the foot. A Velcro-lined sphygmomanometer thigh cuff was placed proximal to the knee and the injection site was positioned 15-18 cm beneath the center of a low-energy (250-keV) parallel-hole collimator of a Nuclear Chicago Pho/Gamma 11/ camera. A ratemeter with a linear scale, a strip-chart recorder, and a 30% spectrometer window were used. Following the injection of 133Xe, the thigh cuff was inflated and maintained at 200-230 mm Hg. The subject then rhythmically dorsiflexed and extended his foot at a rate of 30 times/min. for 4 Y2 min. All subjects were told to exercise as fast and as long as possible at the end of the 4 Y2-min. period. At no time was the duration of ischemia shortened to less than 5 min., and most individuals finished exercising within 5% min. At the end of the ischemic exercise phase, the thigh cuff was rapidly deflated and the rate of disappearance of the radionuclide from the injection site was recorded on a strip chart starting with the initiation of the ischemic exercise phase (in order to confirm the adequacy of the ischemia) and for 5 min. during the ensuing hyperemia. This process was followed for both legs. Maximum blood flow during hyperemia was calculated by plotting the counting rate on semilog paper against time in minutes on the linear scale and using the formula (2)
1964 Lassen et el: (1) first described the use of 133Xe to measure blood flow in the muscles of the lower extremity. Since then the measurement of muscle blood flow (MBF) has not been widely utilized as a routine procedure in many nuclear medicine units, due to the need for elaborate exercise equipment, specially constructed detectors, and maneuvers requiring lengthy intervals to provide meaningful data. Our method for evaluating arterial occlusive disease in the lower extremities avoids these objections and is simple, rapid, and clinically useful. N
METHODS AND MATERIALS
Patients seen in the General Surgery Clinic at the Ann Arbor V. A. Hospital between November 1972 and May 1973 who were suspected of having arterial occlusive disease involving the legs on the basis of the history or physical examination were studied by arteriography. Based on these findings, the legs were assigned to one of three groups. Group I included those limbs demonstrating arterial occlusive disease with poor collateral formation about the aortoiliac, iliofemoral, or femoropopliteal segments. Group" included those having arterial occlusive disease with good collateral formation about the aforementioned segments. Group III included those limbs considered normal on arteriographic examination. Within one week of arteriography, maximum MBF was determined by 133Xe muscle clearance in 62 limbs of 31 men. 133:)(e muscle clearance was also determined in 30 timbs of 15 men who displayed no evidence of arterial occlusive disease by history or physical examination. Informed consent was obtained from all participants. Maximum MBF was determined for each limb as follows. With the subject supine on a stretcher 0.25 ml of 133Xe (200-500 1L Ci) in saline solution was injected into
MBF
=
100 x A x K
1 From the Nuclear Medicine Service and Surgery Service, VA Hospital, and Department of Surgery, University of Michigan, Ann Arbor, Mich. Accepted for publication in May 1975. elk
633
634
V.
RODNEY
,
100
\
\
70
,
" ,,
Subject R.J, MBF = 100 x )" x Ln 2
TY2
w
~
ou
= 38,8 cc /IOOgm/min
7 CUFF RELEASE
5
l,.
ISCHEMIC EXERCISE
3
.,
HYPEREMIA
456
7
8
10
9
TIME (min)
Fig. 1. Calculation of maximum MBF in the anterior tibialis muscle in a normal subject using the 13 3 Xe clearance curve.
80 70
::0·£
60
~~ 50
o.!!! o~ 0:>
T••• J
. , .
~
'.1.'
,
• I. I
cers, gangrenous or pregangrenous skin changes, or pain at rest. The MBF was 14.8 ± 6.0 ml/100 g muscle/ min. (mean ± 1 s.d.; p 0.001 compared to normal limbs) with a range of 4.1-25.7 ml/100 g muscle/min. Nine limbs (mean patient age 54.8 yr, range 46-63 yr.) were shown by arteriography to have arterial occlusive disease with good collateral flow (Group II). This group consisted of 5 patients whose other limb was assigned to Group I (arterial occlusive disease with poor collateral formation) and 2 patients in whom both limbs showed arterial occlusive disease with good collateral formation. These last 2 were thought clinically to have mild intermittent claudication. The maximum MBF for their limbs was 30.1 ± 1.8 mil 100 g muscle/min. (mean ± 1 s.d.: p 0.001 compared to normal limbs) with a range of 28.1-32.6 ml/100 g muscle/min. Maximum MBF for the 9 limbs comprising Group III (patient mean age 47 yr., range 45-50 yr.) was 43.7 ± 4.0 mil 100 g muscle/min. (mean ± 1 s.d.) with a range of 38.8-49.0 ml/ 100 g muscle/min. This group included 3 patients whose opposite limb was assigned to Group I; maximum MBF determinations correctly identified unilateral involvement with arterial occlusive disease. Three additional patients who had symptoms suggestive of atypical claudication were found to have normal arteriograms and MBF studies. All limbs in Group III had maximum MBF determinations within the range of normal.
